Skiving machine



July 26, 1927.-

C. E. THIBAUDEAU SKIVING MACHINE Filed Aug. 5. 1925 pigz. AMEN 727A.

Patented July 26, 1927. v

UNITED STATES PATENT OFFICE.

CHARLES EDWIN TI-IIBAUDEAU, OF IVRY-SUR-SEINE, FRANCE, ASSIGNOR T0 UNITED SHOE MACHINERY CORPORATION, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

SKIVING MACHINE.

Application filed August 5, 1925. Serial No. 48,384.

This invention relates to skiving machines and is herein illustrated as embodied in a machine of the type disclosed in United States Letters Patent No. 1,103,928, granted July 21, 191%; upon an application filedin the names of Bates, Jerram and Gouldbourn.

The patented machine, which is designed more particularly for skiving the edges of parts of boots and shoes, has a dished knife which is a portion of the surface of a sphere, said knife being carried at the'upper end of a rotary shaft. Hitherto it has been customary to solder the knife to a hub and then to fasten the hub tothe shaft. This soldering operation, however, is a diiiic'ult one to perform properly since the knife must be so soldered to the hub that the plane of its cutting edge is exactly at right angles to the axis of the hub; otherwise the knife will not run true when the hub, to'which it is soldered, is fastened to the shaft. These knives wear out rapidly and must be replaced; and hitherto it has been customary for the user of the skiving machine to keep on hand a supply of knives each soldered to a hub in the manner described so as to be prepared to remove and replace this unit when necessary.

The general object of the present invention is to provide a knife and knife mounting which will obviate the necessity of this soldering operation and which will permit the knife to be removed and replaced without ren'ioving the hub from the shaft.

According to one feature of the invention, there is provided a hub adapted to be ias tened to a shaft and having a machined seat, a knife having a machined surface to lit the seat, and a clamping member so connected with the hub as to hold the machined surface of the knife against theseat on the hub. in the illustrative construction the hub is provided with a conical machined surface, and the under side of the knife with a com plementary conical machined surface, and the clamping member engages the knife at three separated localities about 120 degrees apart.

This and other features of the invention will be described as embodied in an illustrative device and pointed out in the appended claims.

Referring now to the accompanying draw 1ngs:

Figure 1 is a section of the hub, knife and clamping member in the positions which they occupy when the knife is clamped to the hub, and

Figure 2 shows in perspective the three parts in separated relation.

The hub 3 is provided with a central bore 5 adapted to fit on a reduced portion of the upper end of the shaft of a skiving machine of the type shown in the patent, the bore being enlarged at its upper end to receive the head of the screw which is threaded into the end of the shaft and holds the hub on the shaft. The hub has a conical seat 7 which is accurately machined so that the apex of the cone lies in the axis of the bore 5. Rising above the conical seat is an annular boss 9; and above the boss is a threaded portion 11 of smaller diameter than that of the boss. The knife 13 which is diskshaped or spherical is stamped from suitable sheet metal by the use of suitable dies and has at its center a hole 15 of a size to fit over theboss9. The dies by which the knife is stamped are so formed as to produce an annular rib 17, which, when the knife is in place, will rest upon the conical seat 7. After the knife has been thus formed, the rib is machined, preferably by grinding, to form a conical surface which is con'iplemei'itary to that of the seat 7.

In order to hold the machined surface of. the knife against the machined surface of the seat 7, a clamping member 19 is provided having a central opening the walls of which are provided with threads 21 adapted to enthe threads of the threaded portion 11 of the hub; and on the under side of the clamping member are formed three projections 25-3 spaced apart about 120 degrees, these projections being so shaped and located as to extend into the annular groove in the top of the knife which resulted when the rib 17 was formed. In order to ensure that the clamping member shall hold the knife firmly upon its seat irrespective of slight made to fit loosely so that the clamping member may rock more or less and thereby accommodate itself to variations such as those mentioned above.

The hub 3 having been fastened to the shaft, the knife is placed on the hub with its opening 15 fitting over the boss 9 and the machined surface on the rib l7 resting upon the seat 7. The clamping member 19 is then screwed down on the threaded portion 11 of the hub, preferably by means of a spanner wrench which is caused to engage holes 25 in the clamping member. The rounded projections 23, which extend into the groove opposite the rib 17, thus engage the knife at three localities and press the conical surface on the rib 17 firmly against the conical seat 7 on the hub. If the knife at the localities engaged by the projections differs in thickness, or if theprojections 23 differ in height or if the threads on the hub or the clamping member are not exactly concentric with the axis of the bore 5, the clamp ing member will accoinnie e itself to such Variations and the knife will run true.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is 1. A device of the class described having, in combination, a hub adapted'to be fastened to a shaft and having a machined surface facing outwardly from the end of the shaft to serve as a seat, a rigid, dished knife having a machined surface to it the seat, and a rigid clamping member adjustable on the hub and shaped to hear at separated localities on the knife.

2. A device of the class described having, in combination, a hub adapted to be fastened to a shaft and having a machined surface to serve as a seat, a knife having a machined surface to fit the seat, and a clamping member adjustable on the hub and shaped to bear at separated localities on the knife, the interengaging portions of the clamping member and the hub being constructed and arranged to permit variation in the relative positions of said members to ensure contact between the machined surfaces under varying conditions.

3. A device of the class described having, in combination, a hub having a conical sur face, a dished knife having a complementary conical surface, and a clamping member engaging the hub and shaped to'bear at separated localities on the knife.

4. A device of the class described having, in combination, a hub having a conical surface, a dished knife having a complementary conical surface, and a clamping member engaging the hub and shaped to bear at senarated localities on the knife, the interengaging portions of the clamping member and the hub being constructed and arranged to permit variation in the relative positions of said member and hub so as to ensure contact between the conical surfaces of the hub and the knife under varying conditions.

5. A device of the class described having, in combination, a hub having a machined surface to form a seat, a boss rising above said surface, and a threaded portion; a dished knife having an opening to receive the boss and a machined surface tofit the seat and a clamping member having threads to engage the threaded portion of the hub and three projections spaced apart to engage the knife, the interengaging threads of the clamping member and the hub being made to fit loosely.

6. A device of the class described having, in combination, a hub having a conical surface, a boss. rising above said surface and a threaded portion; a dished knife having an opening to fit over the boss, and a conical surface complementary to that of the hub;

and a clamping member having threads to enga e the threaded portion of the'hu-b and spaced projections to engage the knife, the

8. A device of the class described having,

in combination, a hub having a machined surface to form a seat, a knife having a central opening and, surrounding the open ing, a portion bent to form an annular groove on one face of the knife and a cor responding rib on the other, said rib having a machined surface to fit the seat, and a clamping member adjustable on the hub and having separatedprojections adapted to engage the groove.

9. A device of the class described having, in combination, a hub having a machined surface to form a seat, a dished knifehaving an annular rib in its underside provided with a surface machined to fit the seat, and a clamping member adjustable on the hub and shaped to bear upon the upper side of the kniie at a locality opposite that on which the rib is formed so as to press the two machined surfaces'firmly together.

In testimony whereof I have signed my name to this specification.

CHARLES EDWIN THlBAUDEAU. 

